1. Field
The disclosed embodiments relate to the construction and operation of a picocell in an aircraft for the wireless transmission of data between at least one mobile station in the aircraft and a base station in an aircraft and to an aircraft having at least one such picocell.
2. Brief Description of Related Developments
In the prior art various different methods and systems are known for enabling passengers in aircraft or on board ships to have mobile communications. This can be the use of telephone appliances, by way of example according to GSM standard, or also of data processing appliances such as laptops or PDAs (personal digital assistants, pocket computers), which have a WLAN (wireless LAN, wireless computer network) interface. When operating cellular mobile radio networks in aircraft a communication takes place between a mobile terminal device in the aircraft, more particularly a mobile radio telephone, and a local mobile radio network (picocell). An ongoing connection into terrestrial networks normally takes place via satellite communications systems. A system is thus provided which enables passengers in a suitably equipped aircraft to conduct telephone calls in a terrestrial communications fixed network from the aircraft.
A method of this kind for operating mobile terminal devices which can be operated in mobile radio networks in transportation means located in space, more particularly aircraft, is described by way of example in DE 10 2004 034 649. With this prior art a communications connection between at least one mobile terminal device located in a transportation means located in space, and one mobile radio network is established by using at least one frequency band provided for aviation purposes.
The electronics in the aircraft for controlling the aircraft can however be very sensitive in their reaction to interferences from an on-board mobile radio network. For this reason passengers are today asked to switch off their mobile radio devices during the flight or to switch them to a purely passive operating state in which they send out no radiation. The passengers and crew members are informed about this by means of suitable announcements or fixed signs (e.g. stickers).
In future however mobile radio networks are also to be set up on board aircraft in order to enable the passengers to have communications connections to the outside even during the flight. The mobile radio devices must only then not be operated if there is a risk of interferences, thus in particularly critical flight phases such as take-off and landing. In other words there are in the next-generation picocells on board an aircraft, flight phases in which the mobile radio devices can be used, and there are flight phases in which the mobile radio devices must not be used.
In the next-generation picocells on board an aircraft the passengers must be notified according to the flight phase as to whether they are permitted to use their mobile radio device or not. An announcement which would have to be made each time for this purpose means additional work for the crew members and is annoying for the passengers who are not affected by the announcement and who do not even want to use their mobile radio devices. There is thus today not the flexibility of signalling to the passengers whether the use of mobile telephones and data terminal devices is currently permitted or not permitted or is possible or not possible.
From EP 0 344 389 a method and apparatus are known for controlling an aircraft. The method thereby comprises the steps: monitoring one or more parameter signals which are characteristic for one or more parameters relating to the aircraft, and identifying the current status of the aircraft at that time according to predetermined status criteria which are defined by the strengths of one or more of the monitored parameter signals wherein the status at that time is one of several predetermined operating states of the aircraft. The signal about the current status at that time is stored in a non-volatile memory means, one or more control signals for the aircraft are supplied. After an interruption in the electrical power the stored signal about the current status at that time is retrieved from a non-volatile memory means, and one or more control signals for the aircraft are supplied which are dependent at least in part on the retrieved signal about the current status at that time.
From the prior published DE 10 2006 036 082 A1 a control apparatus for screening a space is known which screens a space from penetrating signals. For this it has a receiving device, a jamming device and a transmitting device. With the receiving device transmission signals are received from which an interfering signal is determined in order to break down the transmission signal. This interfering signal is radiated via the transmission device.